1. Field of Invention
This invention pertains generally to the art of producing metal or metal oxides distributed in a porous carbon substrate or elf-supported and more specifically to producing such compounds wherein graphite oxide is used as one of the original materials.
2. Description of the Related Art
In the art it is known to provide graphite oxide having foreign organic chemicals inserted therein. For the most part, the organic chemicals are only absorbed by the graphite oxide and do not break the chemical bonds in the graphite oxide. However, exposure of the graphite oxide to H.sub.2 S or CH.sub.3 OH, for example, may result in chemical reactions between the graphite oxide and the organic chemicals to produce organic derivatives of graphite oxide.
Graphite oxide may also be partially reduced by a number of common reducing agents to produce graphite, although complete reduction has not been observed.
Metal oxides, porous or fibrous, may be produced in a sol-gel process which uses metal alkoxide, an organo-metallic compound, to produce a porous metal oxide (or ceramic) compound. After hydrolysis and polymerization, the material is treated by other physical processes (e.g., coating spinning, gelling, precipitation) and then heated to obtain the desired product.
Impregnation of chemical solutions in porous or activated carbon may produce carbon containing metal compounds. Such products are generally carbon with less than 10% by weight of the metal components.
Heating graphite oxide in an inert environment causes thermal decomposition at 150.degree. C.-200.degree. C. If the heating rate is high, the product is a very fine, about 20 .ANG., carbon powder. If the heating rate is low, then the graphite oxide does not disintegrate, but H.sub.2 O, CO, and CO.sub.2 are released, and the product is a graphite-like carbon material which contains a substantial quantity of oxygen. This indicates incomplete thermal decomposition during slow heating to 200.degree. C.
Attempts have also been made to provide reaction products similar to those obtain by the inventive processes using graphite fluoride as an initial reactant.
With reference to the above discussion of the related, it should be noted that graphite fluoride reacts with other chemicals generally around 200.degree. C. to 450.degree. C., although reaction with AlCl.sub.3 may occur at temperatures around 150.degree. C. Fluorine compounds are released during the reactions, which are highly corrosive at such temperatures.
Further, Hennig (1959) summarized the known organic derivatives of graphite oxide. Considering graphite oxide as an organic compound containing the functional groups --OH and .dbd.O, Hennig suggested that graphite oxide could react with organic compounds which are generally reactive to these functional groups. His summary indicates that except for the partial reduction of graphite oxide to graphite by reducing agents, these functional groups are surprisingly inactive.
The sol-gel process is expensive because of its complexity and high price of the reactant.
Lastly, the products from carbon impregnation have low concentration of non-carbon
The present invention overcomes the foregoing difficulties encountered in the art in a way which is simple and efficient, while providing better and more advantageous results.